1. Field of the Invention
The present invention relates to an ignition system for an internal combustion engine which is subject to increased requirements due to (high) boosting and diluted, lowly flammable mixtures (λ>>1, lean layer concepts, high AGR rates).
2. Description of the Related Art
Published U.K. patent document GB717676 shows a step-up transformer for an ignition system in which a circuit component, which is controlled via a vibration switch, is used in the manner of a boost converter in order to supply a spark which is generated via the step-up transformer with electrical energy.
Published international patent application document WO 2009/106100 A1 shows a circuit configuration which is constructed according to a high voltage capacitor ignition system and in which energy, which is stored in a capacitor, is guided, on the one hand, to the primary side of a transformer and, on the other hand, toward a spark gap via a bypass having a diode.
US patent application publication 2004/000878 A1 shows an ignition system in which a secondary-side storage including multiple capacitors is charged in order to supply a spark which is generated with the aid of a transformer with electrical energy.
Published international patent application document WO 9304279 A1 shows an ignition system including two energy sources. One energy source transfers electrical energy with the aid of a transformer to a spark gap while the second energy source is situated between a secondary-side terminal of the transformer and the electrical ground.
It is known that ignition systems for internal combustion engines are based on a high voltage generator, e.g., a step-up transformer, with the aid of which energy originating from the vehicle battery or a generator is converted to high voltages with the aid of which a spark gap is supplied for the purpose of igniting a combustible mixture in the internal combustion engine. For this purpose, a current flowing through the step-up transformer is abruptly interrupted, whereupon the energy stored in the magnetic field of the step-up transformer is discharged in the form of a spark. In order to ensure that the combustible mixture ignites particularly reliably, ignition systems are known from the related art which have multiple chronologically consecutive spark events for the purpose of increasing the probability of the presence of an ignitable mixture at the location of one of the spark events.
Another problem known from the related art is that all the electrical energy which is converted during the spark discharge must be stored in the high voltage generator, whereby the high voltage generator becomes comparably large and thus expensive and requires a lot of installation space.
Due to the discharge characteristic of the high voltage generator, such a high current flows, in particular, at the beginning of the spark discharge that the electrodes of the spark gap are eroded. However, such a high current is not physically necessary to ensure a spark. In this way, only the required duration of the spark discharge is ensured with the acceptance of the previously described disadvantages.
It is therefore the object of the present invention to eliminate the previously mentioned disadvantages of the related art.